DIAGNOSIS A frozen control panel is usually a software glitch in the printer's firmware, not a hardware failure. It can happen after a power surge or during a failed update.
FIX Perform a full power cycle. Turn the printer OFF using the switch on the side, unplug the power cord from the back of the printer for 60 seconds. Plug it back in, turn it on, and wait for it to fully initialize (all lights stop blinking). This clears the volatile memory and reboots the system.
IF THAT DIDN'T WORK If the screen is still dead after a power cycle, there's a small chance the panel cable came loose. You'd have to open the top cover, which isn't recommended casually. More likely, if the power cycle failed, a main board firmware corruption might require a service technician to reload it.
HEADS UP Don't press and hold random buttons trying to force a reset. These don't have a common secret button combo for a hard reset. The full power-down-and-unplug is the correct first step.